As a method of forming a carbon-containing silicon film, for example, a silicon carbide (SiC) film, there is proposed, for example, an atomic layer deposition (ALD) method capable of forming a SiC film by alternately supplying tetrachlorosilane (SiCl4) and trimethyl aluminum (Al(CH3)3) to a workpiece.
However, the SiC film formed by the ALD method has a problem in that large amounts of impurities (Al) are left in the film. Therefore, there is a need for a method of forming a carbon-containing silicon film having low impurity content.